Currently, using a light emitting diode (LED) or an organic light emitting diode (OLED) as a medium of display has been a very common application. When the LED is in a dark state, the screen can be completely turned off by cutting off the current; therefore, compared with a conventional display, the LED has advantageous characteristics of power saving and high contrast. However, the LED element also has a parasitic resistance and a parasitic compensation capacitance, and when the path through which the current flows is cut off, there are residual charges in the LED element, which cause the LED element to emit light. In a dark environment, the light emission is rather obvious, greatly reducing the advantageous characteristics of high contrast and power saving of the LED panel.
Therefore, the problem of reduced contrast and increased power consumption due to residual charges is an urgent issue to be resolved in the industry.